Method for the pressure regulation of a barrier fluid and a pumping device for a method of this kind

Abstract

A method for the pressure regulation of a barrier fluid in a pumping device (10) is introduced, which includes a pump unit (11) with a shaft (12) and a pump housing (13), a drive unit (17), which is mechanically coupled to the pump unit and a shaft sealing arrangement (16.1, 16.2), which seals the pump housing (13) relative to the shaft (12). In the method, a pumping medium is pumped by means of the pumping device (10) and the barrier fluid is conveyed via a feed line (5.1, 5.2) to a common housing (18), in which the pump unit (11) and the drive unit (17) are arranged, in order to prevent a leakage of the pumping medium out of the pump housing (13). Additionally, the pressure of the supplied barrier fluid is increased when a pressure difference between the pressure of the supplied barrier fluid and a detected pressure of the pumping medium in the pump unit (11) falls below a pre-determined value. For this purpose a pressure reducing valve (1) for the differential-pressure is opened and the feed line is connected through to a source (3, 4) for the barrier fluid via the open valve, the pressure of which lies by more than the pre-determined value above the pressure of the pumping medium in the pump unit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a National Stage of International Application No. PCT / EP2008 / 055075 filed Apr. 25, 2008, and which claims the benefit of European Patent Application No. 07108274.7, filed May 4, 2007, the disclosures of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The invention relates to a method for the pressure regulation of a barrier fluid in a pumping device in accordance with the pre-characterising part of the claims herein and a pumping device for a method of this kind in accordance with the pre-characterising part of the claims herein.[0003]Pumping devices for pumping media such as fluids for example, as a rule include a pump unit with a shaft and with a pump housing and a drive unit which is mechanically coupled to the pump unit and also a shaft sealing arrangement which seals the pump housing relative to the shaft. High demands are made on the shaft sealing arrangement if the pump unit and the d...

AI Technical Summary

Benefits of technology

The invention provides a method and device for regulating the pressure of a barrier fluid in a pumping device. The method requires only two pressure valves, reducing the number of components needed for regulation. The valves are directly activated by the pressure difference, ensuring a quick reaction time. The device is designed with a spring to ensure clear behavior in case of breakdown. The method and device are reliable and efficient, using only a few mechanical components for pressure regulation.

Problems solved by technology

Serious damage can arise at the pumping device if the pumping medium which, depending on the use, can also contain solid material components, contaminates critical parts such as bearings.

In a case such as this the entire pumping device may often have to be over-hauled.

The use of pressure / volume compensators results in a comparatively complicated pressure regulating system with a correspondingly large number of components and connections.

Furthermore, pressure / volume compensators contain elastic partition walls which are vulnerable to material fatigue.

If electro-hydraulic pressure valves are used, an electronic pressure sensor and control is necessary and delays in the reaction time of the pressure regulation system result.

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